The present invention relates to golf clubs and, in particular, to iron type golf club heads having an improved weight distribution at the rear club face surface. Iron type golf club heads have been designed with a number of different weighting systems to improve the shot making characteristics of golf clubs. Conventional irons typically are blade types or cavity back, peripheral weight irons. It is understood that the term blade refers to any non-peripheral weighted, iron type club head having an area of generally uniform thickness in a heel to toe direction and having a progressively thicker structure in a top to bottom direction. The blade type iron construction may be formed with a muscle back type bulge which is an area of more concentrated thickness, preferably behind the percussion area on the club face. Other blade iron designs may have a generally flat surface, or be slightly curved, for example, convex or concave, on the rear surface, or variations of the same. The blade iron provides increased feel to a golfer because vibration is evenly transmitted through the uniform thickness of the club head, particularly when a golf ball is struck at or very near the center of percussion on the club face.
Blade types of iron configurations are preferred by professional golfers and other golfers with considerable skill levels because these irons provide better feel when a golf ball is struck squarely on the center of percussion. A well known drawback of these type golf clubs is a loss of feel and shot making performance when the golf ball is struck off the exact center of percussion.
Because most golfers have limited ability, cavity back, peripheral weighted iron designs have been developed. These cavity back, peripheral weighted irons provide a greater moment of inertia to resist twisting and turning of the club head when off-center hits occur during a golf swing. This is accomplished by concentrating the mass of the club head away from the center toward the outer periphery of the club head. This peripheral weight forms a rear cavity on the rear face leaving a thinner mass behind the area of percussion and locates the majority of the rear weight along the bottom, top, and heel and toe portions of the golf club. This peripheral weight configuration produces a more forgiving area of contact, or percussion, allowing less proficient golfers to hit better golf shots to the intended target. The disadvantage of this club head design is reduced feel from the lack of mass or weight concentration behind the center of percussion.
Thus blade irons produce more feel but are less forgiving, while perimeter weighted irons produce greater forgiveness, but have less feel. Various attempts have been made to create an iron club head design that provides the best features of both peripheral weight and blade designs. In my own U.S. Pat. No. 5,562,551, the rear of an iron golf club is formed with an upper peripheral weight and cavity in combination with a flat blade or muscle back surface configuration at the lower portion of the club head. Other examples of iron golf clubs with unique weight configurations are disclosed in U.S. Pat. Nos. 5,395,113, 5,046,733, 5,014,993, 5,011,151, 4,938,470, 4,932,658, 4,919,431, 4,919,430, 4,915,386, 4,907,806 and 4,826,172 to A. J. Antonious, U.S. Pat. No. 3,814,437 to Winquist, U.S. Pat. No. 5,290,032 to Fenton et al and U.S. Pat. No. 5,595,552 to Wright et al. In these patents, the club head designs combine peripheral weight with various supplemental weights on the rear surface of the club head to enhance weight distribution and shot making performance.
The iron type golf club heads of the present invention represent an improvement of the known prior art. The present invention combines the best properties of the blade iron, which concentrates mass behind the center of percussion and the cavity back iron, which places mass to the outer edges. The present invention places mass to the outer edge of the lower area only, concentrating perimeter weight to the lower portion of the club head where the golf ball is hit virtually all the time. Thus the club head design of the present invention provides structural features to maximize golf ball striking performance for both solid and off-center hits. Therefore, a solid hit provides increased feel, as compared to a conventional peripheral weighted cavity back iron, and, off-center hits provide increased forgiveness as compared to a conventional blade type iron golf club.
To accomplish the above, an iron type golf club head is provided with a hosel, a club head body including a heel, toe, bottom sole, top ridge, a ball striking face with a loft greater than 12 degrees, and a leading edge defined by the intersection of the ball striking face and the bottom sole. Preferred embodiments further include a unique rear surface configuration in the form of a weighting system having a peripheral weight and rear cavity formed thereby, which is located on a lower portion of the rear surface of the club head, below the top portion of the rear surface and spaced from the top ridge of the club head. In preferred embodiments, this rear surface weight configuration extends upwardly from the bottom sole on the lower half to as much as the lower two third portion of the rear surface toward the top ridge, the remaining upper portion having a blade type configuration. The overall height, width and depth of the rear peripheral weight may be varied to accommodate golfers of all skill levels and to provide a variety of different ball flight characteristics.
The rear surface weight configuration of the golf club head of the present invention allows all caliber of golfers to improve their shot making, by providing the forgiveness of a perimeter weighted, iron type, golf club, while producing the feel of a blade type golf club. Because golf balls are almost never hit on the club face at or toward the top ridge portion of the club head, the present invention provides a lowering of the peripheral weight found on most conventional golf clubs, to an area on the rear surface adjacent the place on the club face where most golf shots are hit. The peripheral weight on the rear surface of the club head is configured at or around a point on the rear surface that is opposite the center of percussion on the club face. Thus golf balls hit on the center of percussion have the benefit of increased mass configured closer to the center of percussion, whereas golf balls mis-hit toward the bottom of the club head and/or toward the toe or heel of the club head, have the benefit of increased moment of inertia because of the heel, toe and bottom peripheral weight configuration to reduce the effects of twisting the club head, keeping the golf ball in a straighter trajectory toward the intended target. The lowering of the cavity formed by the peripheral weight away from the upper portions of the rear surface of the club head toward the bottom, produces a club head which is more structurally sound therefore producing more solid feel, no matter where impact occurs on the club face.
A primary object of the present invention is the provision of an improved iron type golf club head with a weighting system providing the solid feel of a blade-type club head along with the forgiveness of a peripheral weighted club head.
Another object of the present invention is the provision of an improved iron type golf club head that locates a rear cavity formed by peripheral weight directly behind the area of percussion on the club face.
Another object of the present invention is the provision of an improved iron type golf club head that locates a predominance of weight on its rear surface opposite the area on the club face where most golf balls are struck.
Yet another object of the present invention is the provision of an iron type golf club head having a weighting system that provides a peripheral weight on the lower portion of the rear surface of the club head.
Another object of the present invention is the provision of an iron type golf club head having a peripheral weighting cavity located up to two thirds of the distance between the bottom sole and top ridge on the rear surface of the club head.
Still another object of the present invention is the provision of an iron type golf club head wherein the size and location of the rear peripheral weight may be adjusted to create selected shot making characteristics.
Still another object of the present invention is the provision of an iron type golf club head wherein the mass on the rear of a club head is relocated closer to the area where ball impact normally occurs.
Other objects and advantages of the present invention will become apparent from the following detailed description and drawings, which set forth embodiments of the invention.